Volume 8, Issue 2, July 2013
Prof. Paul KS Chan
Professor, Department of Microbiology, Prince of Wales Hospital The Chinese University of Hong Kong
Introduction
The family Papillomaviridae is comprised of a large group of viruses found in many mammalian species. Infection with papillomaviruses can be asymptomatic or results in the development of benign or malignant neoplasia. Cervical cancer is the most important consequence, in terms of disease burden, of human papillomavirus (HPV) infection. To date, the genomic sequences of more than 150 HPV types have been characterized. Of these, more than 40 types can infect the female genital tract, and at least 15 types are epidemiologically linked to cervical cancer. Over the last few years, there has been a vast increase in using HPV DNA detection as an adjunctive or primary tool in cervica l cancer screening programmes. Primary prevention of cervical cancers associated with the two most common types (HPV16 and HPV18) can now be achieved by vaccination. A thorough understanding on the epidemiology of cervical HPV infection is essential to maximize the clinical benefits and cost-effectiveness of HPV-based diagnostic tests and vaccines. In this review, some key epidemiological features of HPV infection in Hong Kong are presented to assist the formulation of strategies applicable to Hong Kong.
Prevalence of infection
“How common is cervical HPV infection?” This is always the first question to ask before any advice on vaccination can be made. Local studies on “well-women” self-referred for cervical screening showed that the prevalence of cervical HPV infection (defined as having an HPV DNA-positive cervical scrape sample) was around 8% among adult women aged 26-45 years. 1,2 The figure “1 in 12” is recommended for public education. While the studies reported a significant association between number of life-time sexual partners and smoking exposure, the prevalence among those without any recognizable risk factors is high enough to recommend vaccination in general for everyone.